Silane Coupling Agent Content Research Articles

Optimizing the performance of TPCB/SCA composite-modified asphalt using improved response surface methodology

Abstract A composite-modified asphalt was developed by incorporating tire pyrolytic carbon black (TPCB) with a silane coupling agent (SCA) to enhance its ductility and storage stability. The functional binding between asphalt and TPCB was improved by the addition of SCA. The gray correlation comprehensive evaluation method is incorporated into the response surface methodology (RSM), leading to an improved RSM. The improved RSM was employed to optimize the content of the modifier and the preparation process to enhance overall performance. A central composite design-based experiment was conducted to optimize the penetration, softening point, 10°C ductility, Brookfield rotational viscosity, and storage stability indicators of modified asphalt. The response surface of the gray comprehensive evaluation value of the evaluation indicators was calculated using the gray correlation analysis method, and a second-order regression model was established between independent variables such as TPCB, SCA content, and shear time factor and the gray comprehensive evaluation value. This model analyzed the impact of a single variable and variable interaction on the performance of the TPCB/SCA composite-modified asphalt. The optimized model results showed that the preparation parameters that optimize the expected comprehensive performance of the composite-modified asphalt are 9.2% TPCB content, 2.1% SCA content, and a shear time of 56.3 min. Finally, the TPCB/SCA composite-modified asphalt prepared with the improved RSM exhibited the highest gray comprehensive evaluation value and the best overall performance, indicating the feasibility of the optimized preparation parameters with the improved RSM.

Effect and mechanism of waste glass powder silane modification on water stability of asphalt mixture

The loss of adhesion is one of the primary mechanisms of water damage in asphalt mixes containing waste glass powders (WGPs), which is mainly attributed to the smooth surface of the glass may undermine the bitumen–aggregate adhesion and accelerate the stripping. In this study, the WGPs surface was roughened by different types and content of silane coupling agent (SCA), and the surface modification mechanism was illustrated based on the chemical reaction process. Then the adsorption capacity of WGPs on SCA was studied through UV–vis tests, and the effects of the SCA on the chemical composition of WGP and asphalt were investigated by FT-IR tests. At the same time, the adhesion performance between modified WGPs and asphalt was studied by the sessile drop test and column wicking test. Furthermore, the immersion Marshall tests were completed to study the water stability of the asphalt mixture after the replacement of filler with modified WGPs. Results show that the optimal modified time of WGPs is 75 min. During the modified process, a ≡Si-O-Si≡ skeleton structure is generated between the SCA and WGPs, and the amino group in SCA reacts with the carboxylic acid of the asphalt to form a new chemical bond. In addition, adding 10 % KH550 SCA to modify the WGPs will provide the most superior improvement for the adhesion work, stripping work and water stability.

Characteristics, properties and morphology of calcium silicate nanoparticles modified with some silane coupling agents

This paper presents the characteristics, properties and morphology of calcium silicate (CS) nanoparticles modified with silane coupling agents, namely vinyltrimetoxy silane (VTMS) and 3-(trimethoxysilyl)propyl methacrylate silane (MPTS), by the hydrolysis method. Effect of content of silane coupling agents on CS nanoparticles modified was investigated. The obtained results suggested that silane coupling agents were successfully grafted onto the surface of CS nanoparticles. The performance and amount of silane coupling agent grafting on CS nanoparticles depended on the nature and initial content of silane coupling agent. The highest grafting yield on CS nanoparticles performances was 32.8 % for VTMS at initial content of 5 wt. % and 48.80% for MPTS at initial content of 10 wt. %. Organo-modification decreased thermo-oxidation stability of modified CS nanoparticles because of the decomposition of organic moiety in silane coupling agent while hydrophobicity of modified CS surface increased. Thus, agglomeration of modified CS nanoparticles reduced significantly. The unmodified CS nanoparticles had size distribution (in distilled water) peak at nearly 500 nm while the size distribution (in distilled water) peak of CS modified 10 wt.% MPTS was approximately 150nm.

Long-term performance of silane coupling agent/metakaolin based geopolymer

This article reports the effects of different dosages of silane coupling agent (KH-550) on the properties of geopolymer that have been cured for 360 days. The mineral phase formation and microstructure changes of geopolymer were analyzed combined with mechanical properties, XRD, FT-IR, SEM and 29Si NMR. The results show that adding an appropriate amount of silane coupling agent can improve the toughness of geopolymer, and the best performance is obtained when the silane coupling agent content is 0.1 wt%. The highest compressive strength and flexural strength of geopolymer samples containing 0.1 wt% silane coupling agent cured for 90 days reached 51.4 MPa and 12.93 MPa, respectively. The gel phase in the geopolymer is significantly enriched after adding silane coupling agent. Combined with 29Si NMR analysis, it can be seen that the doping of silane coupling agent promotes the polymerization reaction, and gradually develops towards low-aluminum bonded silica and Q4(0Al) structure. The decrease in Q4(0Al) structure of the geopolymer samples cured for 360 days indicates the weakening of the geopolymerization reaction and also explains the decrease in strength after long-term curing.

Effect of Silane Coupling Agent Content on Mechanical Properties of Hydroxyapatite/Poly(methyl methacrylate) Denture Base Composite

In removable prosthodontics, poly(methyl methacrylate) is the most suitable for the construction of denture bases. Intra-orally, the subjected stress intensity during the function accelerate the fracture of acrylic resin denture bases. Extra-orally, fracture occurs when dentures are accidentally dropped on a hard surface. The aim of the current study was to investigate the effect of coupling agent concentration on the mechanical properties of Hydroxyapatite/Poly(methyl methacrylate) denture base composite. The HA treated with four different ratios (i.e. 0, 5, 7 and 10 wt%) of γMPS silane coupling agent was added into the PMMA matrix. The mechanical performance of the composite was evaluated by conducting fracture toughness, flexural and tensile tests. An improvement of 13.83% and 9.62% in the tensile and flexural strength respectively, was achieved. The tensile and flexural modulus of the composite increased by 19.04% and 12.5% respectively. A significant improvement of 29.26% in the fracture toughness was observed at 10 wt% of γ-MPS . 10 wt% of γ-MPS is the optimum amount of coupling agent for obtaining a balanced mechanical properties.

Physical properties and morphology of siloxane–polyacrylate dispersion and coating films

The aim of this work was to study the morphology and physical properties of siloxane–polyacrylate (SPA) dispersion and coating films. The SPA dispersion was synthesized by seeded emulsion polymerization using two different types of silane coupling agents, i.e., vinyltriethoxysilane (VTES) and 3-(trimethoxysilyl) propyl methacrylate (MPTMS), at 1–9% by weight. The effect of the type and content of silane coupling agent used in the SPA dispersion synthesis on the resulting morphology and physical properties of the obtained SPA dispersion and coating films were studied. The results revealed that SPA dispersion synthesized using VTES exhibited a smaller particle size and a higher stability than those using MPTMS. Furthermore, the hydrophobic surfaces and water repellence of the coating films using VTES in the emulsion were higher than those using MPTMS, due to the smoother surface morphology.

Preparation and performance of hydrophobic and conductive silica composite fiber membrane

Electrospinning is an important way to prepare fibers. In this paper, hydrophobic and conductive composite fiber membranes were prepared by opposite electrospinning. The hydrophobic material was trimethylethoxysilane, the conductive material was graphene, and polyvinylpyrrolidone was introduced as the carrier material of graphene. It was found that the sol–gel time, the content of silane coupling agent and low-temperature storage of the solution have a certain influence on the hydrophobicity and spinnability of the fiber membrane. At the same time, the effect of graphene content on the spinnability and the electrical conductivity of composite fiber membrane were studied. The results showed that the composite fiber membrane has good hydrophobic properties and electrical conductivity. The water contact angle of the fiber membrane reaches 139.6°, and the conductivity reaches 1972.78 S cm−1.

Mechanical, thermal, and burning properties of viscose fabric composites: Influence of epoxy resin modification

ABSTRACTThe influence of epoxy resin modification by 3‐aminopropyltriethoxysilane (APTES) on various properties of warp knitted viscose fabric is reported in this study. Dynamic mechanical, impact resistance, flexural, thermal properties, and burning behavior of the epoxy/viscose fabric composites are studied with respect to varying content of silane coupling agent. The results obtained for APTES‐modified epoxy resin based composites reinforced with unmodified viscose fabric composites are compared to unmodified epoxy resin based composites reinforced with APTES‐modified viscose fabric. The dynamic mechanical behavior of the APTES‐modified resin based composites indicates improved interfacial adhesion. The composites prepared from modified epoxy resin exhibited a twofold increase in impact resistance. The improved adhesion between the fiber and modified resin was also visible from the scanning electron microscope analysis of the impact fracture surface. There was less influence of resin modification on the flexural properties of the composites. The 5% APTES modification induced early degradation of composites compared to all other composites. The burning rate of all the composites under study is rated to be satisfactory for use in automotive interior applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46673.

Moisture Effects on NCF Adhesion and Solder Joint Reliability of Chip-on-Board Assembly Using Cu Pillar/Sn–Ag Microbump

Electronic devices as well as electronic packaging technology have required higher speed, I/O capability, and density. To meet these requirements, flip-chip solder bumps interconnection combined with reflow assembly process has been a widely used. In spite of the many advantages of flip-chip solder bump joints, there is a limitation for less than 100 $\mu \text{m}$ fine pitch interconnection due to the solder bump bridging during the assembly process. Therefore, nonconductive films (NCFs) and Cu pillar/Sn–Ag microbump interconnection become a promising interconnection solution for fine pitch assembly. However, NCFs technology has some problems for flip-chip assembly. Epoxy-based NCF can easily absorb moisture, causing delamination reliability problem at moisture environment. In order to solve the interconnection, the NCF adhesion should be enhanced. Silane coupling agent (SCA) was added to NCFs to secure the microbump joint reliability for chip-on-board assembly by increasing the adhesion strength in the pressure cooker test. After the humidity test, the NCFs’ modulus and Tg were increased by adding SCA content. Moreover, the measured adhesion strength and energy showed similar results after the humidity test that higher SCA content showed high adhesion strength and energy than lower SCA content and unmodified NCF at the interface between NCF and solder resist of the printed circuit board substrate. The bump joint lifetime of 5wt% SCA NCF was longer than 1wt% SCA and unmodified NCF after the humidity test. In this paper, we report results of our investigations on effects of employing SCA in NCF composition for improved moisture resistance.

Use of amino silane coupling agent to improve physical and mechanical properties of UF-bonded wheat straw (Triticum aestivum L.) poplar wood particleboard

We evaluated the potential use of amino silane coupling agent (SiNH) to improve physical and mechanical properties of UF-bonded wheat straw (Triticum aestivum L.) poplar wood particleboard. We examined the effects of varied content of silane coupling agent content and ratios of straw to poplar wood particles on particleboard properties. The ratios of straw to poplar wood particles were 100:0, 85:15, 70:30 and 55:45. Silane coupling agent content was tested at three levels, 0, 5 and 10 %. The experimental panels were tested for their mechanical strength, including modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding (IB) and physical properties according to procedures specified in DIN 68763 (Chipboard for special purposes in building construction: concepts, requirements, testing, 1982–03, 1982). All board properties were improved by the addition of silane coupling agent. The use of poplar wood particles had a positive effect on the mechanical properties of wheat straw particleboard but had a negative effect on physical properties (thickness swelling and water absorption).

Cure Characteristics, Mechanical Properties and Abrasion Resistance of Silica Filled Natural Rubber Vulcanizate

Silica which is used for reinforcing filler in tire industry is widely known as eco-friendly material exerting CO2 reduction effect through decrease of rolling resistance and improvement of wet grip. Generally silica is classified as a highly polar filler because it contains a large number of silanol (Si-OH) group on its surface. And also silica gives a lower rein- forcing effect than carbon black due to its poorer rubber-filler interaction. Therefore silica is treated with silane coupling agent or activator, then following the conventional rubber blend method, vulcanized sheets were prepared using a hot press, and cure characteristics, mechanical properties and abrasion resistance of the test specimens were investigated. It was found that with an increase in the silane coupling agent content the tensile strength, 300% modulus and abrasion resistance increased while Mooney viscosity decreased and crosslink density slightly increased with an increase of activator.

Surface characteristics and physical properties of wheat straw particleboard with UF resin

Agricultural fibers, such as straw and plant stalks, have been considered as renewable alternatives for making particleboard, which would ease the huge demand for wood. The objective of this study was to investigate surface characteristic (surface roughness and wettability) and physical properties (thickness swelling and water absorption) of wheat straw (Triticum aestivum L.)/poplar wood particleboard with UF resin and silane coupling agent. The effects of the silane coupling agent content and straw/poplar wood particles ratio on the surface characteristic and physical properties were examined. The ratios of the mixture of straw and poplar wood particles were 100:0, 85:15, 70:30 and 55:45. Silane coupling agent content was chosen at three levels of 0, 5 and 10 %. The experimental panels were tested for their physical properties according to the procedure in DIN 68763 (Determination of values of surface roughness parameters Ra, Rz, R max using electrical contact(stylus) instruments, concepts and measuring conditions, Berlin, Deutsches institut fur Norming, 1982) roughness measurements, average roughness (Ra), mean peak-to-valley height (Rz), root mean square roughness (Rq), were taken from the unsanded samples using a fine stylus tracing technique. Contact angle measurements were obtained by using a goniometer connected with a digital camera and computer system. Results indicated that physical properties (thickness swelling and water absorption (were improved by the addition of silane coupling agent, but use of poplar wood particles has a negative effect on physical properties (thickness swelling and water absorption). Statistical analysis showed that boards consisting of a greater amount of poplar particles exhibited lower wettability. Furthermore, panels made with higher amount of silane level, showed lower Rq values.

The influence of silane coupling agent and poplar particles on the wettability, surface roughness, and hardness of UF-bonded wheat straw (Triticum aestivum L.)/poplar wood particleboard

We used silane coupling agents to improve the bonding ability between wheat straw particles and UF resin, and investigated surface properties (wettability and surface roughness) and hardness of particleboard made from UF-bonded wheat straw (Triticum aestivum L.) combined with poplar wood as affected by silane coupling agent content and straw/poplar wood particle ratios. We manufactured one-layered particleboard panels at four different ratios of straw to poplar wood particles (0%, 15%, 30% and 45% wheat straw) and silane coupling agent content at three levels of 0, 5% and 10%. Roughness measurements, average roughness (Ra), mean peak-to-valley height (Rz), and root mean square roughness (Rq) were measured on unsanded samples by using a fine stylus tracing technique. We obtained contact angle measurements by using a goniometer connected to a digital camera and computer system. Boards containing greater amounts of poplar particles had superior hardness compared to control samples and had lower wettability. Panels made with higher amounts of silane had lower Rq values.

Optimization of Epoxidation Degree and Silane Coupling Agent Content for Silica-Filled Epoxidized Natural Rubber Tire Tread Compounds

Parallel studies on the influence of epoxide contents in epoxidized natural rubbers (ENRs) in the absence of bis-(triethoxysilylpropyl) tetrasulfide (TESPT) coupling agent, as well as a combination of ENRs with different loadings of TESPT on the properties of ENR compounds, are carried out in this work. The results suggests that the best possible combination to optimize processibility and to improve reinforcement efficiency is to utilize ENR with an epoxide content in the range of 20 30 mol%, together with 2 4 wt% relative to the silica content of TESPT. This leads to a reduction of TESPT when compared to the conventional natural rubber compounds.

Surface Modification of Brucite and its Application in Flame Retardant Polypropylene Composites

The surface modification of superfine brucite using silane coupling agent as a modifier was studied. The results of the best modified conditions show that the treated time is 1.5h, the treated temperature is 40°C, the content of silane coupling agent is 7wt%,the stirring speed is 600r/min. In this condition, the activation index up to 93.5%; the treated brucite particles filled into polypropylene(PP), the best tensile strength of 28.63MPa and the LOI of 30% is measured.

Study on the Application of Silane Coupling Agent in Rice Straw/Poly(butylene Succinate) Composites

Rice straw/Poly(butylene succinate)(PBS) composites were prepared by injection molding machine. The influence of content and particle size of rice straw on the mechanical properties of composites indicated that with the increase of rice straw content the tensile strength and fracture strain of the composites was decreased. With the same content of rice straw, the smaller particle size, the more obvious decreased. The influence of dosage of silane coupling agent(SCA) on the composites was studied, the result indicated that with the increase of SCA content, the interface of composite materials significantly improved, the Young’s modulus increased 362% after rice straw was treated by SCA. Thermal analysis showed that the adding of coupling agent didn’t undermine the thermodynamic stability of the composites.

Effects of Silane Coupling Agent Treatment on Properties of PMN/EP Composites

The PMN/EP composites were prepared by resin casting method from PMN powder pretreated with silane coupling agent KH-550. The microstructure of the PMN/EP composite was observed by SEM, the damping property and dielectric property of the composite were investigated by dynamic mechanical analyzer and impedance analyzer respectively. In the composite prepared with PMN powder pretreated by 1.5% silane coupling agent, much epoxy resin fragment is attached in the surface of PMN particles. When the silane coupling agent concentration is 1.5%, the composite shows the best damping property. Dielectric analyses suggest that the dielectric constant of the PMN/EP composite decreases with the increase of silane coupling agent content, however the dielectric loss increases with the increase of silane coupling agent content.

Effects of the content of silane coupling agent KH‐560 on the properties of LLDPE/magnesium hydroxide composites

AbstractBased on traditional idea of molecular coupling effect, surface modifiers were helpful to improve the performances of inorganic/organic composites. However, it was also widely accepted that the content of surface modifier should be controlled in a suitable range, and more or less modifiers could not reach to optimal properties. The intrinsic reason for this phenomenon was not clear until now. In this article, the influences of the content of surface modifier: silane coupling agent KH‐560, on the final performances of linear low‐density polyethylene (LLDPE)/magnesium hydroxide (MH) composites, have been studied. The performance tests of LLDPE/MH composites, including mechanical properties measurements, thermal oxidative stability analysis, and surface morphology observation, all confirmed that there was an optimal content range of surface modifier. However, further morphology investigation of the modified MH by particle size and particle size distribution analyzer showed that, the particle size and particle size distribution of MH both increased as the content of KH‐560 increased. ATR‐FTIR analysis proved that silane grafting was achieved on the MH particle surface, which not only improved the compatibility between MH and LLDPE for molecular coupling effect, but also caused bigger particle size and wider particle size distribution, which were disadvantageous to improve the performances of the composites. The two opposite effects of the surface modifiers mentioned above affected the final performances of the composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Influence of Silane Coupling Agent Content on Crosslink Type and Density of Silica-Filled Natural Rubber Vulcanizates

Crosslink type and degree of crosslink density of a rubber vulcanizate determine the physical properties such as modulus, hardness, resilience, elongation at break, heat build-up, and so forth. By increasing the crosslink density, the modulus, hardness, resilience, and abrasion resistance increase, whereas the elongation at break, heat build-up, and stress relaxation decrease. The stress relaxation, tensile strength, and resilience increase in proportion to the content of polysulfides, whereas the fatigue and thermal aging resistance decrease. Silica and carbon black have been used as the main reinforcing agents in rubber compounds but their surface chemistries are very different. Silica has a number of hydroxyl groups on the surface, which results in strong filler-filler interactions and adsorption of polar materials by hydrogen bonds. Since intermolecular hydrogen bonds between hydroxyl groups on the silica surface are very strong, it can aggregate tightly. Its property can cause a poor dispersion of silica in a rubber compound. The adsorption of curatives by silica results in delay of the scorch time and reduction of the delta torque of a silica-filled rubber compound. The polar surface of silica makes hydrogen bonds with polar materials in rubber compounds. Since the silica surface is acidic, especially it forms a strong hydrogen bond with basic materials. N-tert-Butyl-2-benzothiazole sulfenamide (TBBS) and N-cyclohexyl benzothiazole sulfenamide (CBS) are generally used as cure accelerators for rubbers. Since they have basic functional groups such as amide, they are adsorbed well on the acidic silica surface. The adsorption of curatives to silica results in delay of the scorch time and reduction of the crosslink density in silicafilled rubber compounds. In general, silane coupling agent such as bis-(3-(triethoxysilyl)-propyl)-tetrasulfide (TESPT) is used to improve the silica dispersion as well as to prevent adsorption of curatives on the silica surface. The silane coupling agent reacts with silanol on the silica surface and then a siloxane bond is formed. The silane molecule is bound to the silica surface. In the present work, we studied the influence of silane coupling agent content on the crosslink type and level of crosslink density using silica-filled natural rubber (NR) compounds with different TESP contents. Variation of the crosslink density and type after the thermal aging was also investigated. Sulfur linkages are composed of monosulfide, disulfide, and polysulfides. Polysulfides of the total sulfur crosslinks are enhanced by increasing the elemental sulfur content in a rubber compound. Cure accelerators such as TBBS, CBS, 2-mercaptobenzothiazole (MBT), and tetramethyl thiuramdisulfide (TMTD) make the cure rate of a rubber compound faster. Sulfur linkages, especially polysulfides, can be dissociated by heating and this brings about decrease of the crosslink density. Curatives, especially sulfur, remained in a rubber vulcanizate make new crosslinks and this results in increase of the crosslink density. Figure 1 shows the variations of the crosslink densities with the silane coupling agent content. The crosslink densities of the monoand disulfides, polysulfides, and total sulfur linkages were investigated. All the crosslink densities are enhanced by increasing the silane coupling agent

Effects of silane coupling agent level and extraction treatment on the properties of UF-bonded reed and wheat straw particleboards

Urea formaldehyde resin bonded reed and wheat particleboards with a density of 0.7g/cm3 were manufactured from two types of particle: fine and coarse particles. The effects of the silane coupling agent (SCA) level and ethanol-benzene (EB) treatment on the board properties were examined. For SCA, epoxide silane (SiEP) and amino silane (SiNH) were used for reed and wheat particles, respectively. The results are summarized as follows. (1) For both reed and wheat boards, the internal bond (IB) strength and thickness swelling (TS) were significantly improved at up to 5% SCA content, but the effectiveness of treatment kept constant at above 5%. (2) The level of SCA had little effect on the bending strength, especially for the boards composed of coarse particles. (3) EB treatment upgraded both the IB and TS of wheat board significantly. (4) SiEP incorporation improved the IB and TS of reed board significantly, whereas EB treatment was more effective for wheat board. (5) The dimensional stability of both reed and wheat boards under varying humidity could be improved by increasing the level of SCA and by EB treatment. EB treatment was more effective than SCA addition.